As with chaos, we cannot predict or forecast about the behavior of the complex because all the behaviors do not observe the discipline of system. The behavior of complexity comes from the interaction of agents without any external effect or internal control. This property is known as emergence and brings up the systems the flexibility to adapt and handle it in convert. Approach to complexity theory In order to have an insightful view about the systems, we should view them as wholes. The approaches used in complexity theory are based on a number of techniques, originating from subjects as physics, biology, politics and telecommunications, etc. * Simple Complex systems: this kind of complexity theory refers the individual’s manner which does not change with time. * Complex adaptive systems (complexity science) refer the changes of information when elements changes with time as they learn and react in response to other elements or environment. * Complex cognitive systems: This notion approaches complexity from a psychological perspective, organizational theory and human – computer interaction. * Complex social systems: describes a complex system where individual’s behavior is the result of social agents’ behavior. * Complex responsive processes: this type of theory focuses on the interaction between individuals at the local level, access